Influence of the substrate misorientation on the properties of N-polar GaN films grown by metal organic chemical vapor deposition
Influence of the substrate misorientation on the properties of N-polar GaN films grown by metal organic chemical vapor deposition
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DOI：
10.1063/1.2801406
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发表时间：
2007-10-15
影响因子：
3.2
通讯作者：
Mishra, U. K.
中科院分区：
文献类型：
--
作者：
Keller, S.;Fichtenbaum, N. A.;Mishra, U. K.
采用金属有机化学气相沉积（MOCVD）技术，通过在（0001）取向差的蓝宝石衬底上生长和高温成核工艺的发展，获得了光滑、高质量的N极性GaN薄膜。对蓝宝石衬底的a和m平面的0.5度至4度的取向差角进行了研究。而GaN膜生长在基板上的取向差角只有0.5度或1度表现出高密度的六边形表面特征，通常观察到的N-极性GaN膜生长的MOCVD，光滑的GaN层获得蓝宝石基板上的取向差角为2度或更大。此外，GaN薄膜的结构和光学性能显着改善与增加的取向差角，通过高分辨率X射线衍射，原子力显微镜，透射电子显微镜和光致发光测量进行评估。在具有4度取向差的（0001）蓝宝石上生长的GaN层的性质与在相同反应器中生长的Ga极性GaN膜相当。(C)2007年，美国物理学会。
Smooth, high quality N-polar GaN films were realized by metal organic chemical vapor deposition (MOCVD) through growth on misoriented (0001) sapphire substrates and the development of a high temperature nucleation process. Misorientation angles from 0.5 degrees to 4 degrees toward the a and the m plane of the sapphire substrate were investigated. Whereas GaN films grown on substrates with a misorientation angle of only 0.5 degrees or 1 degrees exhibited high densities of hexagonal surface features as commonly observed for N-polar GaN films grown by MOCVD, smooth GaN layers were obtained on sapphire substrates with misorientation angles of 2 degrees or larger. In addition, the structural and optical properties of the GaN films significantly improved with increasing misorientation angle, as evaluated by high resolution x-ray diffraction, atomic force microscopy, transmission electron microscopy, and photoluminescence measurements. The properties of GaN layers grown on (0001) sapphire with a misorientation of 4 degrees were comparable to Ga-polar GaN films grown in the same reactor. (C) 2007 American Institute of Physics.